It may already be posted but I thought I would let folks know that a non-Viiv PC running Vista makes the media visible on the HR20. You dont need Twonky or any third party tools. I am running Vista RC2 64-Bit Ultimate on an AMD chip. Works pretty well. You just have to configure media sharing on the server.
I signed up for the beta test with Vista. Just had to pay the cost of shipping ($14) and originally Microsoft sent Beta 2, then RC1 the kits included 2 DVD's one for 32 bit the other 64 bit edition. However never got the RC2 edition, I think that's for subscribers of the Technet etc.. only. If you didn't want to get the shipment, you could download vista and burn it yourself to save on the shipping. I prefer just to pay the shipping and get the DVD's. The DVD's will work until sometime in June 2007.
I recently purchased a new PC from Compaq (HP) and I qualify for a free upgrade to Windows Vista Home Premium. Should be getting the DVD by the end of February. If you buy a new PC between October 26, 2006 and March 15, 2007 you get the upgrade for free from Windows XP MCE 2005 SP2. That's worth about $169. versus paying for the upgrade retail. You can send in the receipt provided by the retailer or go online and do the express upgrade. Compaq/HP will provide the upgrade for free. Other manufacturers are charging for the upgrade.
My PC model uses ATI motherboard with Avivo, which I believe is the branding similiar to Intel Viiv. Windows MCE GUI uses my Nero Ultra Editon extreme 7 drivers and is compatible with the ATI Avivo. I have the ATI thearte 650pro TV card installed to which works with Cable/ATSC/DVB-T etc. So I can connect any video/audio via Composite and record from a STB, it even can use Component with the right adapter. I can make copies of movies & programs to the hard drive or burn them to DVD, even content protected programs.